A nuclear bomb detonated in a city or a very populated area has the potential to kill a lot of people. For example, in Bucharest a W87 thermonuclear warfare would kill 250,000 people and injure another 400,000 people
A US-equipped ballistic missile LGM-118A can carry up to 12 W87 warheads
At the same time, a hydrogen bomb "Tsar Bomba" (USSR), the most powerful ever built, would kill over 1.8 million people in the capital.
Nuclear weapons are extremely dangerous, and an organization has developed an online simulator that shows how destructive they can be.
Outrider Simulator, developed by the Outrider Foundation, allows users to detonate virtual nuclear bombs anywhere in the world to see the effects. More information on these weapons can be found on the dedicated website